Asteroid 2012 DA14
The asteroid known as 2012 DA14 will today be making a close approach by the Earth. It’s a chunk of space-rock that was first detected in February 2012.
What’s an asteroid?
An asteroid is one of thousands of small rocky objects in the Solar System that mostly orbit the Sun between Mars and Jupiter. Ranging in diameters of nearly 1000km down to about 10 metres, this particular asteroid is approximately 50 metres in diameter and has a mass of about 200,000 metric tons.
Shown right is the asteroid 433 Eros, imaged by NASA’s NEAR spacecraft in 2001.
Why is this one so close to the Earth?
The orbits of asteroids are sometimes perturbed by the immense gravity of Jupiter, sending the object into the inner Solar System. Occasionally this bring them near to the Earth – hence why they are referred to as “Near-Earth Asteroids”.
Why is it a called “2012 DA14”?
Newly discovered asteroids are given a catalogue designation based on the year in which they were discovered followed by an alphanumeric code determined by the half-month and order in which it was discovered.
Will this impact the Earth?
No, it likely poses no hazard. At closest approach the asteroid will be approx. 30,000 km (~20,000 miles) in distance from the Earth, which takes its path within the orbit of some satellite spacecraft (for example, those used for broadcasting satellite television). So it’s close, but nothing to be concerned about today.
How can I see it?
The asteroid is a relatively small and dim object. But because it’s coming so close to us, it will be possible to observe it in the night sky (from about 7:30pm GMT onwards). However it won’t be a naked eye object that you can just look up and observe – you will need some help from a pair of binoculars or a telescope, and a finder chart like the two shown below.
(Alternatively, if it’s cloudy, there will be several telescopes across the world tracking the asteroid and live streaming video of it. EarthSky.org has good list of the links.)
It will be a challenge, so try to go somewhere as dark as possible and have a go at spotting it. If it’s clear, the planet Jupiter and a crescent Moon will also be on display in the night sky – so have a look at those as well.